The present invention relates to a technique of measuring the frequency dispersion (dielectric spectrum) of complex relative permittivity (hereinafter, abbreviated as complex permittivity) from a liquid containing biological samples such as cells and calculating physical properties of the biological samples or determining the cell type thereof from the measurement result.
A method of measuring an average dielectric spectrum of a liquid which contains plural cells has been known as a technique of measuring a dielectric spectrum of a cell. In this measuring method, unlike the case where the dielectric spectrums of individual cells are measured, an application of distinguishing one abnormal cell from 100 cells on the basis of the measured physical property information of cells is intrinsically impossible.
The complex permittivity or the frequency dispersion thereof is generally calculated by electrically measuring the complex capacitance or the complex impedance between electrodes using a solution retainer having electrodes used to apply an electric field to a solution.
Regarding the technique of measuring dielectric spectrums of individual cells contained in a liquid, an apparatus including a flow channel allowing the individual cells to sequentially flow and two plate electrodes, which are disposed parallel and opposite to each other on a part of the internal surface of the flow channel, with the same size as the cells has been proposed (for example, see NPL 1).